You can remove pages from your notebooks using OneNote for the web with your preferred browser on a PC or Mac.
Removed pages will appear in the Deleted Notes section, so you can restore them later, if needed.
Caution: Unlike the full-featured OneNote desktop apps, where you can use Ctrl+Z (Windows) or ⌘+Z (Mac) to undo your last actions and restore page deletions, deleting pages in OneNote for the web is immediate and cannot be undone. If you're deleting pages from shared notebooks, first make sure that the deletions won't unexpectedly affect other notebook authors.
Do the following:
In OneNote for the web from your preferred browser, go to the section containing the page or subpage that you want to delete.
Do either of the following:
On a PC, right-click the name of the page, and then click Delete Page.
On a Mac, Control-click the name of the page, and then click Delete Page.
Note: To restore or permanently delete a page in OneNote for the web, go to the View tab, then select Deleted Notes. Right click the page name to restore or permanently delete the note. Permanently deleting a note cannot be undone.